In present wireless communication systems it is common for a mobile station (MS) to indicate to a network a set of communication modes it supports. For example in a network supporting the Global System for Mobile Communications (GSM) communication standards the mobile station can indicate that it supports GSM full-rate voice, GSM half-rate voice, GPRS and EDGE communication modes. The mobile station may also transmit an indication that it has advanced receiver capability. For example the mobile station may indicate that its receiver has Downlink Advanced Receiver Performance (DARP) phase 1 and/or or DARP phase 2 capability, each of which is an enhanced interference rejection capability. A receiver having DARP capability can receive and process a wanted signal in the presence of a much higher-level interfering signal than can a receiver that does not have DARP capability.
Indication of DARP capability is outlined in published specification having reference ETSI TS 24.008 V9.3.0 (2010-06) and titled “3rd Generation Partnership Project; Technical Specification Group Core Network and Terminals; Mobile radio interface Layer 3 specification; Core network protocols; Stage 3 (Release 9)”, in section 10.5.1.7 entitled “Mobile Station Classmark 3.” Details of the implementation of DARP are contained in specification having reference “ETSI TS145 015 V5.2.0 (2007-05)”, and titled “Digital cellular telecommunication system (Phase 2+); Release independent Downlink Advanced Receiver Performance (DARP); Implementation guidelines (3GPP TS 45.015 version 5.2.0 Release 5)”.
An indication of DARP capability is transmitted by a mobile station and received by a network apparatus of the wireless communication system. The network apparatus, when it receives the indication of DARP capability, treats the indication as indicating that the mobile station has the indicated DARP capability for all modes of the set of communication modes that the mobile station has indicated it supports.
A mobile station which does not have DARP capability for all the communication modes that it has indicated it supports does not indicate that it has DARP capability. The network will treat that mobile station as though it does not have advanced interference rejection capability for any communication mode. The network will treat the mobile station this way even when the mobile station has advanced interference rejection capability for some, but not all, communication modes which the mobile station supports. It is therefore desirable to provide a means for allowing the network to make use of an advanced interference rejection capability of a mobile station which has advanced interference rejection capability for some but not all communication modes which the mobile station supports. Such a wireless communication system is capable of providing increased actual communication capacity.
DARP Phase 3 is a proposed new specification of advanced receiver capability requirements that is more stringent than the DARP Phase 1 and 2 specifications. Current mobile stations do not have DARP Phase 3 capability. Manufacturers may choose to produce a mobile station which complies with the DARP Phase 3 specification for some but not all communication modes, for reasons of cost. For example, the mobile station may be configured to have DARP Phase 3 capability when it is receiving voice signals but not when it is receiving packet data in EDGE mode. It is therefore desirable to provide an improved wireless communication system that makes use of a mobile station's DARP Phase 3 capability when the mobile station has DARP Phase 3 capability for some but not all communication modes that it supports.
It should be understood that reference to a mobile station in this description may be taken as a reference to a remote communications terminal which may be fixed or mobile.